The biosynthesis of wax esters and triglycerides in bacteria is accomplished through the action of the wax ester synthase/acyl-coenzyme A:diacylglycerol acyltransferase (WS/DGAT or wax ester synthase). A hallmark of these enzymes is the broad substrate profile that accepts alcohols, diglycerides, and fatty acyl-CoAs of various carbon chain lengths and degrees of branching. These enzymes have a broad biotechnological potential due to their role in producing high-value lipids or simple fuels similar to biodiesel through biosynthetic routes. Recently, a crystal structure was solved for the wax ester synthase from Marinobacter aquaeolei VT8 (Maqu_0168), providing a much clearer picture of the architecture of this enzyme and enabling a more precise analysis of the important structural features of the protein. In this work, we used the structure to canvas amino acids lining the proposed substrate-binding pockets and tested the effects of exchanging specific residues on the substrate profiles. We also developed an approach to better probe the residues that alter fatty acyl-CoA selectivity, which has proven more difficult to investigate. Our findings provide an improved blueprint for future efforts to understand how these enzymes position substrates for catalysis and to tailor or improve these enzymes in future biosynthetic schemes.
Bibliographical noteFunding Information:
We thank Carolann Knutson and Peter Rootes for assistance with assays. This work was supported by grants from the National Science Foundation (CBET-1437758), from the National Institute of Food and Agriculture (project nos MIN-12-070 and MIN-12-081), and award no 2020-67019-31148 through the United States Department of Agriculture. N.C.M. thanks the 2020 UMII MnDRIVE Graduate Assistantship for its support. Funding was also provided by the University of Minnesota Grant in Aid program.
© 2022 American Chemical Society.
- Acyl Coenzyme A/metabolism
- Diacylglycerol O-Acyltransferase/metabolism
- Substrate Specificity
PubMed: MeSH publication types
- Research Support, Non-U.S. Gov't
- Research Support, U.S. Gov't, Non-P.H.S.
- Journal Article